In multi-circuit electrical connectors, used in great variety and numbers in communication systems and other data handling systems, the usual technique for connecting individual solid or stranded wire conductors to the connector has been to strip the insulation from the end of the conductor and then solder the conductor to a connector contact. This procedure requires considerable skill on the part of the workman making the solder connection, particularly in miniaturized connectors. There is also a tendency to bridge adjacent contacts of the connector, producing undesired circuit connections.
An alternative technique, gaining increasing acceptance, uses insulation piercing terminals for the contact members of the connector; these terminals cut through the insulation and establish an electrical connection to the conductor without preliminary stripping and without the conventional soldering step. These insulation piercing terminals are usually of forked construction, with cutting edges that penetrate the wire insulation and that also serve as contact jaws that make the necessary electrical connection with the conductor. That is, a forked terminal element on the connector contact serves both as an insulation cutting device and as an electrical contact. A particularly advantageous and effective insulation piercing contact construction, which minimizes cutting into the conductor but provides a firm electrical and mechanical connection, is set forth in the aforementioned application of Hoppe, Serial No. 288,998.
Insertion of the individual conductors into the insulation piercing contacts of a connector unit, such as those shown in the aforesaid Hoppe application, can be accomplished with no special tools, other than an ordinary screwdriver or the like. However, there is a tendency toward inconsistency in carrying out this procedure; if too little pressure is applied and the conductor is incompletely seated, a poor electrical or mechanical connection may be realized, whereas application of excessive pressure may crush the insulation or even break the conductor. Too-deep insertion of a screwdriver or like tool can distort and also damage the insulation piercing elements of the connector contacts. Moreover, the conductor insertion process may still be relatively time-consuming and tedious, so that the advantages of the insulation piercing terminals, relative to soldered terminals, are not fully realized.